function x = nLUDecom(A,n)
%LUDecomposition将矩阵不用列主元Gauss消去法进行三角分解
%L为单位下三角矩阵，U为上三角矩阵，数据储存在A中节省空间
for k = 1:n-1
   A(k+1:n,k) = A(k+1:n,k)/A(k,k);
   A(k+1:n,k+1:n) = A(k+1:n,k+1:n) - A(k+1:n,k)*A(k,k+1:n);
end
x = A;
end

